This invention relates to a system for identifying objects during movement and idicating and/or recording the movements. The invention is particularly concerned with the identification of moving vehicles on a road and is especially adaptable for use in a bus monitoring and control system.
Passengers carried by metropolitan transit companies are normally carried on commercial buses operating over established routes at pre-established schedules. It is known that in order to efficiently utilize the bus equipment and to provide the best service to users of the bus system, it is desirable to maintain the operating schedules of the bus as close as possible with the schedules which have been established for each of the buses in the system. Up to a short time ago, it was usual for most bus systems to rely upon the individual bus operators to maintain their schedule and to avoid disastrous traffic situations and the like. As streets become more crowded, and more people use bus transportation to meet their transit requirements, it becomes manditory to develop a transit control system which accurately controls the schedules of all the buses in the system.
In many cities at the present time, many transit companies place supervisors on street corners for controlling the operations of the buses on routes passing the street corners to which the supervisors are assigned. Communication procedures and devices have been developed in order to assist those supervisors in communicating with dispatchers in order to control and maintain the scheduled operations of the buses in the system. Such a technique, however, is relatively inefficient and requires a large number of supervisors in order to provide the dispatchers with an accurate picture of the operations on each of the different runs or routes of the buses in the system.
To accurately control the scheduling of buses, it is necessary for the dispatchers to know when two buses are running too close to one another, due to either behind-schedule or ahead of schedule buses, thereby providing unbalanced and inefficient utilization of the equipment and disrupting schedules. It is also desirable to know, as soon as possible, when a bus develops mechanical trouble, so that a decision can be made to keep the bus in service, send it to a garage, or stop operation and to provide supplementary equipment to substitute for the disabled bus if necessary. In many situations, the dispatching of emergency equipment to the bus in a short time will enable the placement of the bus back into service without significantly disrupting the service on the route of which the bus is a part.
Since street obstructions either of a semipermanent nature or of a temporary nature, such as accidents, frequently occur on metropolitan transit system routes, it is desirable to be able to alter the buses on the route which is obstructed by such an obstruction, so that immediate action can be taken to direct the buses to alternate street routes if necessary. Finally, in most metropolitan transit operations, increasing problems with safety on the buses are occurring. Robberies, vandalism, and disorderly conduct not only jeopardize the operator but can deter riders from using the transit system. As a consequence, it is desirable to provide the bus operator with a means for summoning help on an emergency basis in an unobtrusive manner.
Electronic systems have previously been used in controller bus monitoring systems in which the location of vehicles following a pre-established route is provided automatically in response to interrogation of the vehicle from a control center.